This invention relates to a tetravalent tin containing monomer. More particularly, this invention relates to a monomer as aforesaid, a polymer prepared from said monomer and a catalyst prepared from said polymer which is useful for transesterification and a process for conducting a transesterification reaction.
Heterogeneous catalysts are known. They are advantageous when used in a transesterification reaction because the catalyst may easily be separated from the reaction mixture whereas additional steps are necessary to separate a homogeneous catalyst from the reaction mixture.
Known polymeric organotin compounds are not effective in catalyzing transesterification reactions because of their lack of selectivity for the desired reaction and the fact that the tin tends to leach out too quickly from the polymer so that only a very few transesterification reactions may be conducted using a polymeric organotin compound.
Polymeric organotin compounds may be prepared from polymerizable tin containing monomers.
Known tetravalent tin containing monomers are not suitable for preparing the transesterification catalysts of this invention because they either do not have the desired functionality for transesterification and the monomer cannot be modified to contain such functionality or the tetravalent tin containing monomer decomposes during polymerization.
It is an object of this invention therefore, to produce a tetravalent tin containing monomer wherein at least one of the ligands is a labile group subject to a specific functionalization.
Another object of this invention is to prepare a polymer, from the monomer, which is a useful in preparing a transesterification catalyst.
A further object of this invention is to prepare a transesterification catalyst which has a high selectivity, high activity and long catalyst life which may be used in a transesterification reaction.
Yet another object of this invention is to provide a process for conducting a transesterification reaction.
Other objects and advantages will become apparent from the following more complete description and claims.